Recently, due to the surge in growth of the industry and the economy, a technology of controlling a relay switch based on a measurement result (for example, overvoltage conduction sensing result, low voltage conduction sensing result, or the like) by a current measuring sensor which is separately attached to measure a current flowing between a driving motor and a battery, for connecting between the driving motor and the battery, which are essentially used in a vehicle (for example, electric vehicle, and the like), using a battery as a main power source has been developed.
Describing a technology relating to the existing relay control as described above, Korean Application Patent Laid-Open No. 10-2007-0023074 discloses a wiper protecting system using an overcurrent of a washer motor, in which a current sensor unit may sense a current input to a washer motor unit to turn on/off a state of a wiper relay based on a sensed current.
However, according to the existing relay control technology as described above, since the current measuring sensor is not connected to the relay but is connected to a circuit and an ECU receives the sensed overvoltage signal from the circuit and then operates the relay based on the received overvoltage signal, the relay may not be preferentially operated which may cause damage to the circuit and threaten the safety of a user when a high current flows in the circuit. In addition to the above the current measuring sensor needs to be separately attached and thus manufacturing costs of the circuit may be increased.
Therefore, to solve the problems of the existing relay control technology as described above, the present inventors have invented a current measuring relay device which may measure a current flowing in a relay and control an operation of the relay based on the measured result without depending on a control of an external control device such as a battery management system (BMS) by integrating the relay with a current measuring sensor to make the relay be preferentially operated when a high current flows in a circuit, thereby protecting the circuit.